Specifically sized at 12-3/4 x 21 x 3/8 inches, ensuring a perfect fit for compatible furnace models. Washable and reusable, this filter outlasts standard air filters, reducing waste. Effectively traps and collects dust and debris, improving the air quality within your home. Supplying Demand replacement parts are compatible with Major Brands, but you should always verify fitment with your specific application. SD products come in Supplying Demand packaging.